Electrical plug and socket spring contact or connector



July 1, 1947.

J. MODREY ELECTRICAL PLUG AND SOCKET SPRING CONTACT OR CONNECTOR Filed May 20, 1943 /o 7 z 4 j a 9 F/GJa 6b, a V v Z 3 SheetsSheet l F/GZ.

. 5 i i LJ h ab 7 Inventor:

H. J. MODREY 2,423,250

ELECTRICAL PLUG AND SOCKET SPRING CONTACT OR CONNECTOR July 1, 1947.

Filed May 20, 1943 3 Sheets-Sheet 2 In uenlor: yaw m A tlorneys.

sggz w,

awwzw H. J. MODREY 2,423,250

ELECTRICAL PLUG AND SOCKET SPRING CONTACT OR CONNECTOR July 1, 1947.

Filed May 20, 1943 3 sheets sneet s Inventor:

Ame

iv 2, l 0m 3,

Patented'July 1 194 UNITED STATES PATENT OFFICE ELECTRICAL PLUG AND socnn'r SPRING con'mc'r on common Henry John Modrey,

This invention relates to plug and socket connectors and has reference both to terminal plugs having a single pin for insertion into a co-operating hole to establish an electrical connection or to plugs and sockets having two or mor pins or contact elements adapted to engage cooperating contacts in a socket.

The primary objects of the invention are to provide connectors which will be positively held in position against accidental displacement due to vibration and to ensure firm electrical contact between adequate contacting areas.

The underlying principle of the invention is to provide such connectors with means whereby when the plug is applied to the socket the plug and socket elements are positively clamped together. p

The invention comprises in its broadest aspect, an electrical terminal plug and socket connector wherein when the plug is applied to the socket the contact element or elements of the plug is or are clamped in conducting engagement to the conducting element or elements within the socket. Thus not only is firm electrical contact established but the co-operating parts are maintained in position against accidental displacement due to vibration.

The clam-ping action is preferably efiected by spring action by means of a clamping bar which can also act as an electrical conductor or earthing contact but in some cases the clamping bar merely acts to clamp the plug to its socket and hold th electrical contacts of the plug in firm engagement with the co-operating electrical contacts of the socket.

An important feature of the construction is that electrical contact is established by spring pressure, the arrangement being such that the plug can be inserted by pressure applied to one casing member operating to compress the spring in one directirn and can be disconnected by a pulling force applied to another casing member operating to compress the spring in the reverse direction.

In order that the invention may be readily understood and carried into practice, reference is hereby made to the accompanying diagrammatic drawings, wherein various forms of connectors constructed according to the invention are illustrated by way of example. In these drawings Figure 1 is a sectional view of a single pin terminal connector in position in its socket;

Figure 1a is a partial sectional view of a modification of Figure 1:

London, England, assignmto Modrey Patents C orporation, Essex County, N. J., a corporation of New Jersey 7 Application May 20, 1943, Serial No. 487,761 In Great Britain May 27, 1942 11 Claims. '(Cl. 173-328) 2 construction of plug and socket illustrating how a number of electrical leads can be connected in circuit;

Figure 3 is a view partly in section illustrating a two pin plug and socket and also showing how branch circuits can be connected;

Figure 4 is a plan view of the socket shown in Figure 3;

Figure 5 shows a modified detail of socket designed to protect the operator against any possibility of shock, and

Figure 6 shows in section a further modified construction of a connector.

Referring to these drawings and particularly to Figur l, the numeral I designates an insulating cap through a grip 2 of which the insulated electrical lead 3 passes. The conducting core 4 of this lead is soldered or otherwise electrically connected to the conducting cap 5 contained within the insulating cap i. A sleeve 6, of insulating material, closed at its lower end by a metal bush 1, is arranged to be telescopically slidable within he conducting cap 5. A clamping rod 8, which in this instance also constitutes an electrical conductor, is bent over at one end to form a clamping head So and at its other end is. welded to the top of the conducting cap 5.

Surrounding this clamping rod 8 a compression spring 9 is arranged tending to separate the tele scoping parts 5 and 6. This spring is provided with a tail or wedging extension 911.

The cross section of the clamping rod 8 is part of a circle and may conveniently be semi-circular and the cross section of the tail or wedging extension 90. of the spring is of a cross section such that a cross section through the clamping rod 8 and the tall or wedging extension 9a is circular. That is to say, the sections of the two parts are complementary and together substantially fill the hole in the metal bush 1 through which they both pass. If the cross section of the clamping rod is semi-circular the cross section of the tail or wedging element will also be semi-circular and it will be understood from the foregoing that the flat faces of the two elements 8 and 9a abut and are longitudinally slidable one along the other. The socket I0 is of insulating material and has within it a metal conducting disc or plate H to which th electric lead i3 is soldered or otherwise electrically connected.

To make the plug and socket connection the telescoping parts 5 and 6 are collapsed so that the spring 9 is compressed and the clamping head 8a extends beyond the tail piece or wedging ex- Figure 2 is aview partly in section of a modified 5g tensio 51;, ior example by applying opposing pressures to the cap I and projecting members] 4. This can, in practice, be effected by pressure applied to the cap I with the clamping head 8a in position at the entrance to the hole in the conducting disc II. The clamping head can then be passed through the hole in the conducting disc II of the socket and when the spring 9 is again allowed to expand the telescoping parts 5 and 6 will again separate and the tall or wedging extension 9a of the spring will follow up and enter and substantially fill up the hole in the conducting disc II and the clamping head 8a will be held by the spring action firmly against the underside of the conducting disc II which will thus be securely clamped between the clamping head 81: and the metal conducting bush 1 of the plug, and electrical connection will be established through the conducting rod 8 and the edge or knife contact between clamping head 8a and the lower edge of the hole in conducting disc I I. The spring pressure will always tend to produce a satisfactory electric contact at this point.

To withdraw the plug from the socket it is only necessary to exert a pulling force upon the sleeve 6, the projecting members I4 facilitating this action.

It should be mentioned that where the conducting disc I I is fixed in the socket Ill, there must be sufiicient clearance between the sleeve 6 and the socket I to permit slight relative lateral movement while the plug is being inserted. An alternative method of providing for this slight lateral movement is to provide a floating conducting disc. Thus, in the foregoing example, if it should be desired that the sleeve 6 be a close fit in the socket I0, it would be necessary to leave the conducting disc loose and of sufiiciently smaller diameter than the recess in the socket III in which it is located to permit the slight movement necessary. Figure 1a shows such an arrangement. Disc or plate II is disposed in a recess I 0' providing sufficient clearance to allow for the required lateral movement of disc II. As will be noted, sleeve 6 can then be inserted with a close fit into socket Ill.

Figure 2 shows much the same construction, the cap being provided, however, with a metal plunger 5a which operates to compress the spring and a pin 61: is provided on the casing 6 which can be engaged with a bayonet slot la in the rim of the insulating cap I, so that when the telescoping parts have been collapsed ready for insertion in the socket, they can be held by a slight rotary movement of the cap I, and after insertion of the plug into the socket and reverse movement of the cap I, will disengage the parts and permit the spring to operate. A nose 6b 0n the outside of sleeve 6, similar to registering nose 3| ofFigure 3, can be employed to cooperate with a slot in the rim of the socket Illa to register the two parts together. The device shown in this figure is, as will be obvious, intended for the connection, end to end, in a line circuit. A grip 2' similar to grip 2 serves to protect lead I3 against pull or other stress exerted upon the plug-socket unit.

Referring now to Figures 3 and 4 there is there shown an arrangement operating in similar fashion but having two connection pins side by side.

In this arrangement the structure is of elongated form as shown in Figure 4, with the two clamping and contact making elements arranged side by side. Referring to the drawing, I5 is an insulating cap within which a metal piston I6 is secured, the electrical leads I1 being sui a y 0 nected to this piston, for example by set screws I Ia enclosed within a protecting insulating cover I1b. The clamping rods I8, which in this instance again also act as conductors, are welded or otherwise secured to the piston and the springs I9 with their wedging extension I9a surround the clamping rod as previously described with relation to Figures 1 and 2.

The insulating casing 20 is recessed on its inner wall and a leaf spring 2| provided with a projection 22 is anchored at its upper end in this recess. A hole 23 is provided in the flange of the insulating cap I5 and when the parts are telescoped together by applying opposing pressures to the cap I5 and the projections 24 of the casing 20, th projection 22 of the spring 2I snaps into the hole 23. The plug can then be inserted into the socket 25 with one of its clamping bars in each of the holes 25a and upon release of the projection 22 from engagement in the hole 23 the springs I9 will effect th clamping action in the manner hereinbefore described. The insulating casing 20 may be provided with a, positioning nose 3! adapted to register a slot in the upper flange 33 of the socket.

In some cases, with the making of the plugs and sockets shock proof, it may be desirable to adopt the construction shown in Figure 5 which is distinguished from the constructions hereinbefore described in that electrical contact is made on the back face or underside of the conducting contact element 5| of the socket, which element is arranged beneath the top wall 52 of the insulating socket casing 53, the circuit in this case being through the clamping rod 54, acting as an electrical conductor, as well as a clamping element in a manner which will be clearly understood from the foregoing.

In some cases, particularly with small sizes, it is not practical to construct the wedging extension or tail integral with the spring, as the wedging extension requires to be reasonably stiff, and if the same section is used for the spring, the spring may be too stifl for convenient operation. In such cases the constructionshown in Figure 6 may be adopted. In this arrangement an insulating cap 53 is provided enclosing a, metal cap 54 in which an insulating sleeve 55 slides telescopically much as before described with relation to Figures 1 and 2. The sleeve 55 is provided with i a metallic liner 56. Two or three turns 51 of the D section wire are provided integral with the wedging extension 58 but the spring action is derived from a lighter circular section spring 59 which is anchored between the two turns 51 of the thicker wire. The spring 59 is welded to the cap 54. The clamping rod 60, which in this case is also an electrical conductor, is connected to an electrical lead 6|. The operation is as before described with reference to the before described constructions, but by reason of the lighter spring the telescoping of the parts is more easily effected, and the spring, although of lighter construction, will be found to be suflicient to eifect a satisfactory clamping action.

The manner in which plugs according to the invention are inserted into and withdrawn from their sockets has already been indicated with relation to the plug shown in Figure 1 and it will be understood that in all cases when inserting the plug the part to which the clamping rod is attached must be so operated as to extend the clamping head beyond the wedging extension and when withdrawing the plug from the socket the part which compresses'the spring and carries the wedging extension out or its wedging position will be'operated, suillcient play between the plug and socket elements being provided to prevent Jamthe hole in said plate when the plug is inserted in the socket, a relatively rigid electrically conductive clamping rod slidable in said opening and having a clamping head outside said wall member, an electric conductor connected with said plate, a second electric conductor in permanent metallicconnection with said rod; spring means normally retaining said clamping rod in withdrawn position with said clamping head seated against the exterior of said wall member. wedge means biased by the spring means on said plug preventing passage of said clamping head through said hole when the plug is inserted in the socket with the clamping head penetrating through and seated against said conducting plate, and means for applying pressure manually to said clamping rod to slide said rod with its clamping head into a position relative to the wedge means in which the joint cross-section of the rod and the wedge means is smaller than the crosssection of the hole for passage through said hole, said clamping head being heldagainst withdrawal through said hole by said wedge means upon release of the manually applied pressure.

2. In an electrical connector, the invention as recited in claim 1 wherein said plate and said end wall member comprise said cooperating contacts, said plate having integral resilient lugs for engaging the lateral'surface of the end wall memher.

3. An electrical connector plug comprising a pair of telescoped casing sections made of insulation material, a wall supported at the end of one casing section, said wall having an opening therethrough, an electrically conductive member mounted within the other casing section, an electrical conductor connected with said member, an electrically conductive clamping bar slidable through said opening and secured at its inner end to said member, spring means within said casing sections tending to separate the same and withdraw said clamping bar from said opening, the outer end of said clamping bar terminating in a clamping head that engages the exterior of said end wall to limit the withdrawal of said clamping bar, and a wedge member biased by said spring means extending through said opening and laterally aligned with said clamping head, said clamping head being projected beyond said end wall and wedge member for insertion through a hole in a conductive member of a socket by compressing said spring means and being latched to said socket member and electrically connected therewith by movement of the wedge member into the hole upon expansion of the spring means to withdraw the clamping bar.

4. An electrical connector plug as recited in claim 3, wherein said spring means comprises a relatively heavy spring having an end thereof extended through the opening of said end wall to constitute said wedge member, and a relatively light spring between said first spring and said other casing section.

6 5..An electrical plug connector as recited in claim 3, in combination with a spring contact carried by said first casing section and insulated irom said conducting wall, and means for conmeeting an electrical lead to said spring contact.

6 In an electrical connector, the combination of a socket having a plate with a hole therethrough, a plug for insertion in said socket, and cooperating electrical contacts carried by said socket and said plug; said plug including an end wall member having an opening therethrough in substantial alignment with the hole in said plate when the plug is inserted in the socket, a relatively rigid clamping rod slidable in said opening and having a clamping head outside said wall member, spring means normally retaining said clamping rod in withdrawn position with said clamping head seated against the exterior of said wall member, wedge means on said plug preventing passage of said clamping head through said hole when the plug is inserted in the socket with the clamping rod in withdrawn position, said wedge means comprising the intergral end of a spring element of said spring means, said integral end extending through said opening of the wall and being aligned laterally with said clamping head when said clamping rod is withdrawn by said spring means, and means for applying pres sure to said clamping rod to slide said rod with its clamping head into a position relative to the wedge means in which the joint-cross-section of the clamping rod and the wedge means is smaller than the cross-section of the hole for passage through said hole, said clamping rod being held against withdrawal through said hole by said wedge means upon release of the applied pressure.

7. An electrical connector plug comprising a pair of telescoped casing sections, a, conducting Wall supported at the end of one casing section, said wall having an opening therethrough, a clamping rod slidable through said opening and secured at its inner end to the other casing section, spring means within said casing sections tending to separate the same and withdraw said clamping rod from said clamping opening, the outer end of said clamping rod terminating in a clamping head that engages the exterior of saidend wall to limit the withdrawal of said clamping rod, and a wedge member comprising the integral end of a spring member of said spring means, said wedge member extended through said opening and laterally aligned with said clamping head, said clamping head being projected beyond said end wall and wedge member for insertion through a hole in a conductive socket member by compressing said spring means and being latched to said socket member by movement of the wedge member into the hole upon expansion of the spring means to withdraw the clamping rod.

8. In an electrical connector, in combinationa socket having a plate with a hole therethrough, a, plug for insertion in said socket, and cooperating electrical contacts carried by said socket and said plug, said plug including an end wall member having an opening therethrough in substantial alignment with the hole in said plate when the plug is inserted in the socket, a relatively rigid clamping rod slidable in said opening and having a clamping head outside said wall member, spring means normally retaining said clamping rod in withdrawn position with said clamping head seated against the exterior of said wall member, wedge means on said plug preventing passage of said clamping head through said hole when the plug is inserted in the socket with the clamping head penetrating through and seated against said conducting plate, said wedge means comprising the integral end of a spring element of said spring means, said integral end extending through said opening of the wall and being aligned laterally with said clamping head when said clamping rod is withdrawn by said spring means, -and means for applying pressure to said clamping rod to slide said rod with its clamping head into a position relative to the wedge means in which the jolnt-cross-sectlon oi th clamping rod and the wedge means is smaller than the cross-section of the hole for passage throughsaid hole, said clamping rod being held against withdrawal through said hole by said wedge means upon release 01' the applied pressure, said opening through the end wall being of substantially circular cross-section, and said clamping rod and wedge means having complementary cross-sections substantially filling said opening.

9. In an electrical connector, in combination a plug comprising a pair of telescoped casing sections made of insulation material, a wall supported at the end of one casing section, said wall having an opening therethrough, an electrical conductive member mounted within th other casing section, an electrical conductor connected with said member, an electrically conductive clamping rod slidable through said opening and secured at its inner end to said member, spring means within said casing sections tending to separate the same and withdraw said clamping rod from said opening, the outer end of said clamping rod terminating in a clamping head that engages the xterior of said wall to limit the withdrawal of said clamping rod, and a wedge member biased by the spring means extending through said opening and laterally aligned with said clamping head; and an insulation socket member comprising an electrically conductive plate with a hole therethrough mounted within the socket, and a second electrical conductor connected with said socket plate, said clamping head being projected beyond said end wall and wedge member for insertion through the hole in said socket plate by compressing said spring means and being latched to said socket member and electrically connected therewith by movement of the wedge member into the hole of said socket plate upon an expansion of the spring means to withdraw the clamping rod.

10. In an electrical connector, in combination a plug comprising a pair of telescoped casing sections made of insulation material, a wall supported at the end of one casing section, said wall having an opening therethrough, an electrical conductive member mounted within the other casing section, an electrical conductor connected with said member, an electrically conductive clamping rod slidable through said opening and secured at its inner end to said member, spring means within said casing sections tending to separate the same and withdraw said clamping rod from said opening, th outer end of said clamping rod terminating in a clamping head that engages the exterior of said wall to limit the withdrawal of said clamping rod, and a wedge member biased by the spring means extending through said opening and laterally aligned with said clamping head; and an insulation socket member comprising an electrically conductive plate with a hole therethrough mounted within the socket, and a second electrical conductor connected with said socket plate, said clamping head being projected beyond said end wall and wedge member for insertion through the hole in said socket plate by compressing said spring means and being latched to said socket member and electrically connected therewith by movement of the wedge member into the hole of said socket plate upon an expansion of the spring means to withdraw the clamping rod, said socket member including a cup-shaped portion arranged to receive the casing section supporting said end wall when the plug is latched to the socket, thereby forming a plug-socket unit having a substantially continuous surface of insulator material.

11. In an electrical connector, the combination of an insulator socket having therein a conducting plate with a hole therethrough and mounted transversely slidably in said socket, and of an insulator plug for insertion in said socket, said plug including an end wall member having an opening therethrough in substantial alignment with the hole in said plate when the plug is inserted in the socket, a relatively rigid, electricai conductive clamping rod slidable in said opening, said rod having a clamping head outside said wall member, an electric conductor connected with said plate, a second electric conductor in permanent metallic connection with said rod, spring means normally retaining said clamping rod in withdrawn position with said clamping head seated against the exterior of said wall member, wedge means biased by the spring means on said plug preventing passage of said clamping head through said hole when the plug is inserted in the socket with the clamping head penetrating through and seated against said conducting plate, and means for applying pressure to said clamping rod to extend said clamping head beyond said wall member for passage through said hole, said clamping head being held against withdrawal through said hole and in electric contact with said plate by said wedging means upon the release of the applied pressure.

HENRY JOHN MODREY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,387,814 TenBosch Aug. 16, 1921 2,034,695 Dougherty Mar. 24, 1936 2,322,852 Kost June 29, 1943 2,379,134 DeMooy June 26, 1945 2,234,938 Degener Mar. 11, 1941 2,280,403 Finkle Apr. 21, 1942 FOREIGN PATENTS Number Country Date 507,331 Germany Sept. 15, 1930 571,528 Germany Mar. 2, 1933 

